GROWTH AND PRODUCTION OF TWO CASTOR BEAN CULTIVARS UNDER NPK FERTILIZATION

The actual paper was carried out aiming to evaluate the effects of nitrogen, phosphorus and potassium on the growth and seeds production of castor bean (Ricinus communis L.), cultivar BRS Nordestina and BRS Paraguacu. For each cultivar an experiment was conducted in a greenhouse, in Campina Grande, PB. Each experiment was conducted on a 2 x 2 x 2 factorial design completely randomized resulting 24 experimental units, subjected to the following levels of fertilization: nitrogen (200 and 300 kg ha(-1)), phosphorus (150 and 250 kg ha(-1)) and potassium (150 and 250 kg ha(-1)). Plant height, stem diameter, number of leaves and leaf area were measured at 20, 40, 60, 80, 100, 120, 140 and 160 days after planting. At the end of the experiment the weight of seeds was measured. Nitrogen was the nutrient that promoted the highest growth and yield for both cultivars; the phosphorus and potassium application did not influence the stem diameter, leaf area and the yield of castor bean; the highest plant height was obtained with the treatment N1P1K1 (200-150-150 kg ha(-1)).